Yarn drying apparatus



`7 l? 'i941' H. s. DRUM HTM.

YARN DRYING APPARATUS Filed Feb. 27, 1941 5 Sheets-Sheet l INVENTOHS 61 rawz/ H fg. DRUM ET AL YARN DRYJNG APFARATUS Illa H. S. DRUM ET Ai..

YARN DRYING APPARATUS Y Filed Feb. 2'7, 1941 www? 3 Sheets-heet 3 new @@wwww Patented Dec. 15, 1942 2,304,897 YARN DRYING APARA'rUs Harry S. Drum and William C. Dodson, Abington,

Pa., assignors to Smith, Drum and Company, Philadelphia, Pa. a corporation of Pennsyl- Vania,

Application February 21, 19in, serial No. 380,758

Claims.

The present invention relates to the drying of material following a treating, washing or other wet processl during the transformation of that material into flnishedform, and relates more particularly to the drying of yarn in package form. y

In the drying of wet material it has heretofore been proposed to control the drying apparatus by the varying humidity of the drying medium, such as air, which surrounds and circulates about the material. Another method has been to employ a mechanism which is responsive to theI change in weight of the mass of material as it dries. Neither of these methods has been entirely satisfactory and have inherent disadvantages. By reason of the fact that material oi substantial thickness does not dry uniformly it is essential that drying temperatures, such as followr the use of humidity or weight controls, must be kept below a safe temperature so as not to damage that portion of the material which has dried first. In thus maintaining a safe temperature the time for complete drying is far longer than would be required were it possible to use the required high temperatures. into added cost of production.

Some of the objects of the present invention are to provide a drying apparatus in which the foregoing disadvantages are eliminated; to provide a drying apparatus arranged to ensure 5' uniform drying of a yarn package or a relatively thick piece of material; to provide means for so controlling the drying of material that the eiliclency due to high drying temperatures can be maintained without damage to the material; to A provide a drying apparatus capable of compensating the drying time relative to the texture of the material, since heavy yarns, for example, require a different drying time than do fine yarns; to provide a control means whereby an average drying temperature can be secured for a plurality of yarn packages; and to provide other improvements as will hereinafter appear.

In the accompanying drawings Fig. l represents diagrammatically a sectional elevation of a package drying apparatus embodying one form of the present invention; Fig. 2 represents a fragmentary side elevation showing the heat exchange unit; Fig. 3 is a diagram of one system of circuits used for control purposes in the invention; Fig. 4 represents a diagram of a modified form of drying control.

Referring to the drawing, one form of the present vinvention is shown as arranged for use with yarn packages I0, mounted upon a carriage This loss of time translates itself type of carrier II which can be wheeled into and out of a door controlled cabinet I2. In this type of carrier, a chamber I3 is formed by a casing Il and `serves to distribute heated air to the interior of the packages I0 by way of holes I5 which communicate respectively with the`ends of the channeled spindles I6. The tubular perforated tubes carrying the packages are mounted respectively upon these spindles I6, as is well known in the art and thus heated air enters the axis of each package and travels radially outward to dry-the packages.

As shown by way of example the inner end wall of the casing I4 is provided with an inlet opening Il so located as to register with the outlet I8 of a heat exchange unit when the carrier .is in operative association with the cabinet I2. This unit consists of a box 2|, having an air inlet 22, and steam coils 23 located between the inlet 22 and outlet I8. The heating medium, preferably steam, is supplied by a pipe 24 from a suitable source, while air is supplied to the box 2l from a blower 25 driven by an electric motor 26. An interlocking connection, such as a clamping latch 2l, serves to anchor the carrier to the cabinet with a leak proof joint about the outlet from the transfer unit.

From this construction it will be seen that the packages are dehumidified and dried by heated air passing through them from the inside to the outside, or vice versa. Circulation of the air within the cabinet I2 is maintained by one or more overhead fans 28 ydriven respectively from the exterior of the cabinet by an electric motor or' motors 30. It should be kept in mind, however, that this described apparatus is but one example of an apparatus suitable for use with the invention, so that the particular manner in which the packages are heated is of minor 'nnportance as compared to the direct control of yarn package drying.

For the purpose of shutting off the supply of steam to the heating coils 23 a thermal type of valve 3I is located in the steam supply pipe 24 and is arranged to cut off the steam when the electric circuit of conductors 32 and 33 is closed. It is believed unnecessary to describe this valve structure in detail because it is a well known valve having anl enclosed bulb containing a heat responsive medium to develop sufiicient pressure under the radiated heat of a coil to close the valve. The conductors 32 and 33 are in a circuit including a main switch 34, a source of current supply LII..2 and a relay switch 36, this last being normally open so that the control thermal valve 3| is open.

In order to close the relay switch 36 when the temperature within a package I reaches a predetermined maximum, the magnet coil 31, for the switch 36, is in an electric circuit including conductors 38 and 39, the main switch 34, and a control element in the form of a circuit closing thermometer 4|] of a size and shape to be readily inserted endwise of a yarn package. 'Ihe terminals of the conductors 38 and 38 are led through the glass wall of the thermometer body in such spaced relation that at the selected maximum temperature the expanding mercury column 4| will bridge such terminals and close the circuit of relay coil 31 to thereby close the switch 36 and energize the steam valve 3| as required to cutoff the steam supply.

For notifying the operator that the switch 36 has closed the control circuit, a visual signal, in the form of a lamp 42, and an audible signal in the form of an electric bell 43 are arranged in parallel in the control circuit so that both are energized as the steam is cut off. This indicates to the operator that the package temperature has reached the desired maximum, and the package is ready to be removed.

Since it is advisable to have the steam shut oi when access is to be had to the cabinet, a double pole two way switch 44 is shown in shunt relation across the switch 36 and has its contactor 45 under the pressure of a spring 46 to move it in the direction to close the thermal valve circuit by way of conductors 41 and 48. A plunger 45a is connected to the contactor 45 and is arranged to be pressed inwardly by the closingy of the door or other closure of the cabinet to overcome the action of the spring 46 so that the valve circuit is open and the parallel circuit for the signals set to respond to the closing of the switch 36.

For controlling the blower motor 26, a three phase current is supplied by conductors 48, 58 and 50a under `control of a magnetic contactor unit of well known commercial form, Briey, three switches 52, 53 and 54 are located in the respective conductors 49, 5|) and 50a and have contactors 55, 56 and 51 arranged to be simultaneously opened or closed by the action of the armature of magnet or solenoid coil 58. A maintaining switch contactor 60 is also operated by the solenoid coil 58.

A source of current L1L2L3 supplies the three phase current to the conductors 43, 58 and 56a when the magnetic contactor switches are closed. The maintaining switch contactor 60 electrically connects contacts 62 and 63 when the solenoidy coil 58 is energized to keep the solenoid circuit closed as will later appear.

As a means to start and stop the blower motor 26, a well known type of switch unit 64 ls provided having a starting push button contactor 65, which is normally spring-held to break a cir--v cuit between contacts 66 and 61, and a stop push button contactor 68 normally spring-held to electrically connect contacts 16 and 1|. The contacts 66 and 10 are connected by a conductor 12 to the contact 62, while contact 61 is connected by a conductor 13 to both the contact 63 and the coil 58. Contact 1| is connected by a contuctor 14 to the current supply line L1. 'I'he return conductor of the coil 58 leads through a pair of overload switches 16 to the line L2 by Way of a normally closed relay switch 11.

In order to control the operation of the fan motors 30, a magnetic contactor unit 80, similar to the contactor unit 5|, is connected in parallel with that unit to the source of current LlLzLJ and is under the control of a starting and stopping unit 8|, like the unit 64 plus a maintaining switch 82 like switch 60. The two contactor units 5| and 80 have the respective solenoid circuits supplied from the source L1L2 and include common return conductor 15 which is normally closed by the switch 11. It is believed unnecessary to describe the units 80 and 8| in detail, as each should be understood from the description of the units 5| and 64.

For the purpose of breaking the circuits of the contactor units 5| and 80 to stop the blower 25 and fans 30 when the selected package temperature has been attained the normally closed side of the supply line.

switch 11 is provided under the control of a relay magnet 83 in the circuit of conductors 38 and 39. Thus when the thermometer contacts close the circuit to energize the relay magnet 31, the relay magnet 83 is also energized, The former therefore closes the circuit. to cut off the steam, while the latter opens the circuit for the blower and fans.

In the operation of the apparatus the control element 40 is set to close the circuit 38 and 3l at a predetermined temperature at which the dryer is to be automatically shut down and, with the control element inserted into the package as shown, the apparatus is then ready to function. The doors of the cabinet are closed and this action moves the door switch 45 to break the circuit 41 and 48 including the valve 3| and at the same time partially closes the circuit for the bell and lamp signals. Since the valve 3| is now deenergized it opens and allows steam to be delivered to the heat exchange coils and, therefore, the blower and fans are ready to be started. Since the two separate magnetic contactors and starting buttons operate exactly alike but on different motors, the starting circuits will be confined to but one of these as the other will be merely a repetition. The starting push button 6,5 closes the circuit between the contacts 66 and 61 thereby permitting current to flow by way of conductor 13 to the magnet coil 58 and return by conductor 15 and conductor 11 to the other The energizing of the magnet coil 58 shirts the solenoid contactor to not only close the contactors 55, 56 and 51 of the several line switches but also throws the contactor across the contact 62 and 63 whereby the circuit is maintained closed `ancl the starting push button short circulted. The blower motor is thus in operation and upon a like push button closing of the unit 8| a similar circuit closing takes place and the fan motors 36 are in operation.

Heated air is now circulating from the inside of the packages to the outside and when the temperature of the package used as a control reachesv that predetermined one, the mercury column 4| closes the circuit 38 and 39 which results in relay 83 being energized to open switch at contactor 11 and to energize relay 31 to close contactor Il. The opening of the switch formed by contactor 11 breaks the circuit to the two magnetic contactor coils and thus brings both the blower motor and fan motors to rest. The closing of the switch formed by contactor 36 closes the circuit to the thermal valve 3| 'which is thus heated and brought to a closed position cutting off steam to the heating coils. Also closing the contactor 36 results in energizing the bell and lamp circuits may he finished cold while others may be finished hot; different kinds of dyes; different diameters of packages; and the density oi the wind. Because of these variations all packages do not dry with the same speed. Heretofore it has been customary to manually remove a number of packages from the drier and weigh them in order to obtain an average from which it is determined whether or not all the packages are dry. Obviously this is not only a crude method but an unpleasant and uncertain one because the opertor facing a hot chamber naturally grabs out those packages most conveniently located and hence does not obtain a true average condition. By the present invention these disadvantages and uncertainties are eliminated because the instruments are precisely located at widely separated points and hence a real average condition is indicated automatically and no sample packages have to be removed.

Having thus described our invention, we claim: l. In a drying apparatus, the combination of means to introduce air into a yarn package to travel therethrough for drying purposes, a heating unit for said air supplied from a source of heat. means for circulating said air over said unit, and means responsive to the internal temperature of said package for regulating the supply of heat to said unit.

2. In a drying apparatus, the combination of means t introduce air into a yarn package to travel therethrough for drying purposes, a heating unit for said air supplied from a source of heat, means for circulating said air over said unit, and means responsive to a predetermined temperature within said package for lowering the temperature of said unit.

3. In a drying apparatus, the combination of means to introduce air into ayarn package to travel therethrough for drying purposes, a heating unit for said air supplied from a source of heat, means for circulating said air over said unit, and means including a thermal responsive instrument inserted in said package for lowering the temperature of said unit when a predetermined temperature is reached within said package.

4. In a drying apparatus, the combination of means to introduce lair into a yarn package to travel therethrough for drying purposes, a heating unit for said air supplied from a source of heat, means for circulating said air over said unit, a pipe from said source to said unit, a valve in said pipe, and means responsive to a predetermined temperature within said package for operating said valve.

5. In a drying apparatus, the combination o1' means to introduce air into a yarn package to travel therethrough for drying purposes, a heating unit for said air supplied from a source of heat, means for4 circulating said air over said unit, means including a normally open electric circuit for controlling the temperature of the heat supply to said unit, and a thermal responsive instrument in said package arranged to close said circuit at a predetermined temperature to lower the temperature of the heat supply to said unit.

6. In a drying apparatus, the combination of means to introduce air into a yarn package to travel therethrough for drying purposes, a heating unit for said air supplied from a source of heat, means for circulating said air over said unit means including an electric circuit for controlling the temperature of the heat supply to said unit, and a thermometer in said package arranged to control said circuit at a predetermined temperature t0 lower the temperature of the heat supply to said unit.

'7. In a drying apparatus, the combination oi means to introduce air into a. yarn package to travel therethrough for drying purposes, a heating unit for said air supplied from a source oi' heat, a pipe from said source to said unit, a valve in said pipe, a blower for circulating said air over said heating unit, electrical means for operating said blower, and means responsive to a predetermined temperature within said package for closing said valve and also rendering said blower operating means ineffective.

8. In a drying apparatus, the combination oi' means to introduce air into a yarn package to travel therethrough for drying purposes, a heating unit for said air supplied from a source oi heat, a blower for circulating said air over said heating unit, electrical means for operating said blower, and means responsive to a predetermined temperature within said package for rendering said blower operating means ineffective.

9. In a drying apparatus, the combination of means to introduce air into a yarn package to travel therethrough for drying purposes, a heating unit for said air supplied from a source of heat, means for circulating said air over said unit, a motor driven fan for circulating air about the outside of said package, and means responsive to a predetermined temperature within said package for stopping said fan.

lO. In a drying apparatus, the combination of means to introduce air into a yarn package to travel therethrough for drying purposes. a heating unit for said air supplied from a source of heat, means for circulating said air over said unit, and means located respectively at different places in a yarn package and responsive to the temperature at said places for independently lowering the temperature of the heat supply to said heating unit.

11. In a drying apparatus, the combination o! means to introduce air into a yarn package to travel therethrough for drying purposes, a heating unit for said air supplied from a source of heat, means for circulating said air over said unit, means including a thermometer located within and adjacent the core of said package for reducing the temperature of the heat supply to said heating unit at a predetermined yarn temperature, and means including a thermometer located within and adjacent the outer layer of said package for also reducing the temperature oi the heat supply to said heating unit at a predetermined yarn temperature.

i2. In a drying apparatus, the combination of means to introduce air into a yarn package to travel therethrough for drying purposes, a heating unit for said air supplied from a source of heat, means for circulating said air over said unit, means responsive to a predetermined temperature within and adjacent the outer layer of said yarn package for reducing the temperature of me heat supply to said heating unit, and means operating on said heating unit to prevent the temperature adjacent the core o! said package from rising above a predetermined temperature.

13. In a drying apparatus, the combination of means to introduce air simultaneously into a plurality of yarn packages to travel therethrough for drying purposes, a heating unit for said air supplied from a source ot heat, means for circulating said air oversaid unit. and means, including temperature responsive devices respectively in a plurality of said packages, for reducing the temperature of the heat supply to said heating unit when the temperature in any one of said yarn packages rises to a predetermined maximum.

14. In a drying apparatus, the combinationv means to introduce air simultaneously into a plurality of yarn packages to travel therethrough for drying purposes, a heating unit for said air supplied from a. source of heat, means for circulating said air over said unit, means including temperature responsive devices located respectively in said packages adjacent the cores thereof for reducing the temperature of the heat supply to said heating unit when the temperature adjacent the core o! any one of said packages rises to a predetermined maximum, and means, including temperature responsive devices operative to further reduce the temperature of the heat supply to said heating unit when the temperature adjacent the outer layer of al1 of said packages rises to a predetermined maximum.

HARRY s. DRM. WILLIAM C. DoDsoN. 

